In high frequency and high power electrical applications, the application of power to associated equipment involves inherent risks which are of a constant concern to both manufacturers and users of such equipment. Power must be applied in a manner which will not damage the equipment, and in a manner which provides a safe environment for users. For example, when high power (i.e. kilowatts) RF signals are transmitted along a cable which is disconnected from a load, i.e. on an open circuit, the energy may be reflected back to the signal source, thereby destroying the same. Also, if a conducting material is in close proximity to the end of the cable through which the high power signal is applied, the signal may arc across an air gap to the conducting material. This could cause serious risks of electrical shock, equipment damage, or fire.
Another concern relates to the risk of electrical shock to the users of the high power equipment. When power is applied along a cable which is disconnected from a load, it is possible that a user may come into physical contact with the "hot" end of the cable. This can occur, for example, through the inadvertent direct contact with the center conductor of the cable, or by inadvertent contact of a hand tool with the center conductor. Regardless of the manner of contact, however, sufficient power to seriously injure or kill a person is frequently applied to the cable. Prevention of contact with the center conductor of the cable is, therefore, of extreme importance.
To date, users of high-power RF equipment have generally been left to their own resources to limit the risks associated with the application of a high power signal to an open circuit. Most users are highly cognizant of the risks, and are careful to connect a load to a signal source before applying power. Human error and accident, however, frequently result in serious injury to users and damage to equipment.
There is, therefore, a need in the art for electrical connectors, particularly connectors for use in high power RF applications, which are capable of switching the RF signal source off when the connection between the signal source and the load is removed.